Topical Therapies for the Management of Recalcitrant Chronic Rhinosinusitis

Abstract

This thesis encompasses research investigating topical therapies to improve the management of recalcitrant chronic rhinosinusitis (CRS). Chapter one of this thesis reviews the current literature pertaining to CRS including its aetiopathogenesis and the role of the sinonasal microbiome. It also outlines current management and factors leading to poor outcomes after surgery such as bacterial dysbiosis, inflammation and scarring. The use of two topical agents Chitogel®, a hydrogel composed of chitosan and dextran, and deferiprone, an iron chelating drug are reviewed for their potential to improve surgical outcomes. A review of sinonasal delivery devices for topical delivery of medication is presented with particular reference to intranasal nebulisers. The second chapter presents a double-blinded randomised controlled trial to investigate the effect that Chitogel has on the sinonasal microbiome and infections following endoscopic sinus surgery (ESS). Chitogel was found to significantly improved both the nasoendoscopic appearance of the sinuses and sinus ostial patency at 12 weeks postoperative. Significantly, Chitogel was also found to restore a healthier microbiome following ESS, resulting in an increase in the relative abundance of beneficial commensals Corynebacterium and Cutibacterium (Propionibacterium). In keeping with the improvement seen in the microbiome, a significant decrease in postoperative infections was noted following use of Chitogel.